Performance of growth and productivity of several maize varieties in the dry land ecosystem

. This research activity aims to determine the growth and productivity performance of several maize varieties in the dry land of the Karo district. The study was conducted in Kutabangun Village, Tiga binanga district, Karo Regency from February to June 2019. This study used a Randomized Block Design with the treatment of 4 varieties of corn with the same components of the corn plant technology package as the integrated corn crop management approach. The varieties tested were: 1.) Pioneer 32, 2.) NK 22, 3.) BIMA 20 and 4.) NASA 29 and as replicates. 5 (five) farmers. Each farmer planted 4 varieties of corn on an area of 1 ha, so the land required for this test was 5 ha. The results of observations of dry-shelled seed weight (t/ha) showed that there was a significant difference between the four varieties planted where the dry-shelled seed weight (t/ha) ranged from 7.68 to 8.53 t/ha. The highest dry seed weight (t/ha) was produced by the Pioneer 32 variety, which was 8.53 t/ha, followed by the NK 22 (7.95 t/ha), NASA 29 (7.82 t/ha), and BIMA 20 ( 7.68 t/ha). Net income per hectare/season produced by the Pioneer 32 varieties (Rp. 19.490.000), Nasa 29 (Rp. 17.170.000), BIMA 20 (Rp. 16.65 million), and the NK 22 varieties (Rp. 16.090.000) and The B/C ratio per hectare of each variety is the Pioneer 32 (1.33%), Nasa 29 (1.17%), BIMA 20 (1.13%) and the NK variety 22 (1.12%).


Introduction
Maize is the second food crop after rice which is the government's priority to increase its production.Apart from providing food for a large part of the population nationally, maize is also a raw material for the feed industry.Compared to wheat and rice, maize is a more versatile multi-purpose crop.In developed economies, it is primarily used as a livestock feed crop with a varied roles as an industrial and energy crop [1].It is known to be the third biggest grown crop in the world, although maize is a rich source of carbohydrates, it also contains a valuable amount of other macronutrients like protein, fat, minerals, and vitamins.The expansion of maize plantations to increase current and future production is mostly directed at dry and acid lands which are classified as marginal and full of constraints, namely toxicity and certain nutrient deficiencies in dry acid [2].Around 60 percent of maize cultivation in Indonesia is done on dry land [3].The average yield of dry-shelled hybrid corn in dry land at the farm level is still low, around 3.7 t/ha, and often experiences failure due to the varieties planted are not resistant to drought [4].
Geographically, Karo Regency has an area of 2,127.25 Km 2 or 2.97 percent of the total area of North Sumatra Province.Most of the population work in the agricultural sector.This district is one of the largest corn producers in North Sumatra.Maize farming is one of the businesses of choice for farmers in Karo Regency considering the natural conditions that are suitable for corn plants.
The Agricultural Research and Development Agency (BALITBANG) has produced various technological innovations that can increase the productivity of food crops, including high-yielding varieties some of which have been cultivated and developed by farmers.The results of the research by Jaya et al [5] on dry land in the rainy season with sufficient water, yields of several hybrid varieties were obtained, namely BISI-816 of 6.26 t/h; Pioneer-21, 6.84 t/h; Pertiwi-2, 5.78 t/h, and NK-212 at 6.98 t/h.Superior varieties were one component of technology that has a real role in increasing the production and quality of agricultural commodities.The use of superior seeds in the field by the community is still relatively limited.The main problems in corn cultivation are biotic and abiotic factors, traditional cultivation techniques, the use of varieties that have low yield potential, low plant populations, and the use of fertilizers that are not optimal [6].While the Application of inorganic fertilizer is important to maize yields [7].Several important factors that need to be considered to increase corn production include the use of new high-yielding varieties, optimum fertilization, and regulation of the planting population.
Several high-yielding maize varieties that have been released have wide adaptability, but in specific agroecological conditions, testing is still needed to see the response of plants to these specific agroecological conditions.Maize varieties produced through population improvement need to be tested in planting areas that have different agro-climates to determine their response to the local environment [8].The yield of hybrid corn will be optimal if it is supported by fertilization carried out with the right dose, time, and method [9].
In general, the types of corn plants that are tolerant of drought stress include high biomass before the female flowers come out, stay green and the leaves are thicker and waxy.Characters related to drought include germination, growth, photosynthesis, development of reproductive organs and seed formation, and yield components [10].Characteristics related to drought are plant height, flowering, and yield.The ability of plants to maintain green leaves (stay green) during drought affects the ability to fill seeds and ultimately affects yields [11].To find out the superiority of corn varieties in the dry lands of North Sumatra, several varieties were tested in one of the corn plant centers in Karo Regency.

Materials and methods
The assessment activities were carried out in the Karo district.The activity starts from January to December 2019.In this study, we follow the existing cropping pattern in this area.The assessment is designed under the cultivation technology approach to increase productivity, the technology applied, is presented in Table 1.Land preparation was done by plowing, harrowing, and leveling.Organic fertilizer fertilization was given at a dose of 500 kg/ha given as a cover for planting holes.The dose of inorganic fertilizer for upland rice plants given consisted of: 250 kg urea + 150 kg KCl, + 200 kg SP 36, and 300 kg Ponska.Pest and disease control was implemented under the principles of integrated pest control (IPM).Control is carried out if crop damage by pests and diseases has reached the control threshold.Parameters observed were: plant height, length of corncobs, diameter of the corncobs, the height of corncob position, age of harvest, productivity before shelling, and shelled productivity t/ha.Analysis of the design data used Randomized block design, farmers as replicates, and varieties as treatment 1).Pioneer 32, 2).NK 22, 3).BIMA 20, and 4) NASA 29.Further test data using LSD test.The farming system analysis was calculated based on operating costs and revenues.Farming was considered financially and economically feasible if the Gross B/C value was more than one.The value of B/C> 1 means that upland rice farming is feasible to be implemented and developed more widely.

Results and discussion
The plant height of all varieties planted showed a significant difference, the highest plant was NASA 29 variety (247.87 cm), which showed a significant difference with the NK 22 variety with plant height (208.90 cm) while the NASA 29 variety ( 247.87 ) and BIMA 20 (234.23) did not show a significant difference.(Table 2).The average plant height of the 4 varieties tested ranged from 208.90 cm to 247.87 cm.The variety that has the shortest plant height is the NK 22 variety, which is 208.90 cm.Plants that grow short will be resistant to falls and are favored by farmers.In general, the appearance of the maize varieties tested for plant height was included in the high category.Variations in the appearance of plant height of the varieties tested were influenced by genetic and environmental factors.In general, the farmers of Kutabangun Village plant corn using the Pioneer 32 and NK 22 varieties, and the appearance of the plant height is included in the tall category.The fastest 50 % flowering population age was found in the BIMA 20 variety (60.00) days after planting (DAT) and the NASA 29 variety (62.67)DAP was significantly different from the Pioneer 32 variety and the NK 22 variety (66.00) and (67.00) days after planting.The low flowering time of plants was influenced by the genetics of the plant itself and local environmental conditions.Flowering time is critical in deploying varieties across environments, impacting yield and seed quality in maize [12].Plants that flower earlier will have a faster harvest period, and it has the potential to increase the cropping index per year.The timing of male and female flower maturation, or flowering time, greatly influences the potential grain yield at harvest time [13].The numbers followed by the same letter mean not significantly different at 0.05 LSD The results of observations on the length of the corncob (cm) of the tested varieties showed significant differences (Table 3.).The longest corncob length was obtained from the Pioneer 32 variety, which was 17.93 cm, not significantly different from the NASA 29 (17.73 cm) and, but significantly different from the NK 22 and BIMA 20 varieties with their respective lengths (16.20 cm) and (16.87 cm) The differences in the appearance of the length of the cob of the varieties tested were influenced by genetic and environmental factors.The results of observations on the diameter of the corncob planted showed that the corncob ranges from 4.33 to 4.69 cm.The highest corncob diameter displayed by the PIONEER 32 variety (4.69 cm) was not significantly different from that of the NK 22 variety and the BIMA 20 variety.However, it was significantly different from the NASA 29 variety, which was 4.33 cm.The numbers followed by the same letter mean not significantly different at 0.05 LSD The result also showed that the variety with the highest corncob position was the NK 22 variety, which was 133.20 cm, not significantly different from the Pioneer 32 variety and the BIMA 20 variety with 131.60 and 132.33 cm, respectively (Table 4.).But it was significantly different from the height corncob position of the NASA 29 variety, only with a height of 128.80 cm from the ground.Varieties with lower corncobs will make harvesting easier and reduce the risk of collapsing due to wind.
The observations showed that the age of harvest of maize varieties was significantly different.The age of harvest ranged from 117.33 to 126.67 days after planting (DAP).The BIMA 20 variety gave the fastest harvest age (117.33 DAP) not significantly different from the NASA 29 variety with a harvest age of 118.00 DAP, but significantly different from the NK 22 and Pioneer 32 varieties with 123.00 and 126.67 DAP, respectively.Early harvest is beneficial for increasing cropping intensity in one cropping pattern and for increasing maize production with three plantings index in a year.Varieties that have a faster harvest age will be able to increase planting intensity in one year.The numbers followed by the same letter mean not significantly different at 0.05 LSD In Table 5, it can be seen that the productivity before shelling and productivity of shelled t/ha, are influenced by the variety of maize planted, the lowest productivity before shelling was shown by the NK 22 variety, which was 9.61 t/ha not significantly different from BIMA 20 variety is 9.76 t/ha.This result was significantly different from the results of the Pioneer 32 variety and the NASA 22 variety.The highest was shown by the Pioneer 32 variety and the NASA 29 variety (10.67 t/ha and 10.06 t/ha).The productivity of shelled (t/ha) showed a significant difference between the four varieties planted where the productivity of shelled (t/ha) ranged from 7.68 to 8.53 t/ha.The highest productivity of shelled (t/ha) was produced by the Pioneer 32 variety, which was 8.53 t/ha, significantly different from the productivity of shelled (t/ha) of the NK 22, NASA 29, and BIMA 20 varieties.The three varieties NK 22, NASA 29, and BIMA 20 did not have different productivity of shelled (7.95 t/ha, 7.82 t/ha, and 7.68 t/ha).The numbers followed by the same letter mean not significantly different at 0.05 LSD The financial analysis of maize farming showed each of the varieties of Pioneer 32, NK 22, NASA 29, and BIMA 20 planted by farming per hectare spent the same production cost of Rp. 14,630,000, most of these costs are allocated for payment of wages from planting to harvesting, amounting to Rp. 8,325,000, and part of it was used to purchase production inputs of Rp. 6,305,000, with the provision of such inputs, productivity, or the resulting output if valued at the current price of each commodity, then farmers receive gross income per hectare with each variety Pioneer 32, Rp. 34,120,000, NK 22 Rp. .30,720,000, NASA 29 Rp.31,800,000, and the BIMA variety Rp. 31,280,000,.For the largest net income per hectare/season, the Pioneer 32 variety, Rp.19,490,000, Nasa 29 Rp.17,170,000, BIMA 20 Rp. 16,650,000, and the NK 22 variety is Rp.16,090,000,.The B/C ratio per hectare of each variety was Pioneer 32, 1.33%, NASA 29 1.17%, BIMA 20 1.13%, and NK 22 variety 1.12%.The smallest cost for each variety to produce 1 kg of maize is as follows: Pioneer 32, Rp.

Table 1 .
Maize cultivation technology was applied to food crop farming systems in the upland dry land.

Table 2 .
The average result of observations of plant height and flowering age of 50%.

Table 3 .
The average results of the length of the corncob and diameter of the corncob.

Table 4 .
The average results of the height of corncob position and the age of harvest.

Table 5 .
The average results of Productivity before shelling and Productivity of shelled.