Yield Of Marketable Ears Research Articles

Planting Geometry May Be Used to Optimize Plant Density and Yields without Changing Yield Potential per Plant in Sweet Corn.

Planting geometry is one of the most important management practices that determine plant growth and yield of corn. The effects of eight planting geometries (35 × 23 cm, 40 × 21 cm, 45 × 19 cm, 50 × 18 cm, 55 × 17 cm, 60 × 16 cm, 65 × 15 cm, 70 × 15 cm) on plant growth and yields of three sweet corn hybrids (Argos F1, Challenger F1, Khan F1) were investigated under Erzurum, Türkiye conditions in 2022 and 2023 years. Variance analysis of the main factors shows a highly significant effect on whole traits but in two-way interactions some of the traits were significant and in the three-way interactions, it was insignificant. As an average of years, the number of plants per hectare at the harvest varied between 92,307 (35 × 23 cm) and 120,444 (70 × 15 cm) according to the planting geometries. The highest marketable ear number per hectare (107,456), marketable ear yield (24,887 kg ha-1), and fresh kernel yield (19,493 kg ha-1) were obtained from the 40 × 21 cm planting geometry. The results showed that the variety Khan F1 grown at 40 × 21 cm planting geometry obtained the highest marketable ear number (112,472), marketable ear yield (29,788 kg ha-1), and fresh kernel yield (22,432 kg ha-1). The plant density was positively correlated with marketable ear number (r = 0.904 **), marketable ear yield (r = 0.853 **), and fresh kernel yield (r = 0.801 **). The differences among the varieties were significant for the studied traits, except for plant density and kernel number per ear. In conclusion, the variety Khan F1 should be grown at the 40 × 21 cm planting geometry to maximize yields under study area conditions without water and nutrient limitations.

Soil-biodegradable Mulches for Growth, Yield, and Quality of Sweet Corn in a Mediterranean-type Climate

Plastic mulch is commonly used to produce many vegetable crops because of its potential to decrease days to harvest, control weeds, and improve soil moisture conservation. However, use of plastic mulch is relatively new for sweet corn (Zea mays L.) in North America. We compared five plastic soil-biodegradable mulches [BDMs; Bio360, Organix AG, Clear Organix AG, Naturecycle, and Experimental polylactic acid/polyhydroxyalkanoates (Metabolix, Inc., Cambridge, MA)] and a paper mulch (WeedGuardPlus) against standard black polyethylene (PE; nonbiodegradable) mulch and bare ground cultivation for growth, yield, and quality of sweet corn cultivar Xtra Tender 2171. This field experiment was carried out in Mount Vernon, WA, which has a Mediterranean-type climate with an average air temperature of 16.1 °C during the 2017 and 2018 growing seasons. The experiment was drip irrigated; and in both years, preemergence herbicides were applied to the entire experimental area 1 to 2 days after seeding, and post-emergence herbicides were applied to alleys. While most mulches remained intact until the end of the growing season, Clear Organix AG started to split shortly after laying, resulting in significant weed pressure by midseason in both 2017 and 2018. Plant height toward the end of the season was lowest for plants grown on bare ground, intermediate for Clear Organix AG and WeedGuardPlus, and highest for the black plastic BDM and PE mulch treatments both years, except for Bio360 in 2018 where plant height was intermediate. Days to 50% tasseling and 50% silking were delayed 9 and 13 days, respectively, for bare ground and WeedGuardPlus compared with all other treatments in both years. Marketable ear yield was highest with the black plastic BDMs and PE mulch and lowest with bare ground, WeedGuardPlus, and Clear Organix AG treatments in both years. Total soluble solid content of kernels, and length and diameter of ears grown on the plastic BDM and PE mulch treatments were equal to or greater than, but never lower than, bare ground and WeedGuardPlus. These results indicate that growth, yield, and quality of sweet corn grown with black plastic BDMs are comparable to PE mulch, making black plastic BDMs an effective alternative to black PE mulch for sweet corn production in a Mediterranean-type climate.

Effect of plant density on growth and yield of extremely late-planted korean sweet corn hybrids (Zea mays L.) for fresh market

Sweet corn has a short growing period of 80 to 90 days in Korea, which allows famers to grow this crop using various cropping systems. This objective of this study was to find the optimum plant density for Korean sweet corn (se) hybrids ‘Godangok’ and ‘Guseulok’ when they were grown as the second crop. Plant densities were 5,710, 6,670, and 8,000 plants 10a-1 and planting dates were 20 July and 30 July, 2013. There was no interactive effect between plant density and hybrid for all the analyzed parameters in this study. Increasing plant density up to 8,000 plants 10a-1 led to no significant gain in marketable ear yield. Although the total number of ears was increased about 21 c 33% at the highest plant density than at lower densities, e.g., 6,670 or 5,710 plants 10a-1, the percentage of marketable ear number and individual ear weight decreased with increasing plant density. Individual ear weight of marketable ears was significantly greater, e.g., by 8 c 13%, at 5,710 plants 10a-1 and 6,670 plants 10a-1 than at 8,000 plants 10a-1. Similar results were obtained for ear length and width and filled length under the given plant densities, which indicated that increasing plant density may decrease individual ear fresh weight and ear size with good tip fill. Increasing plant density up to 8,000 plants 10a-1 caused the lowest harvest index, which resulted in little gain in fresh ear yield compared to the lower plant densities of 5,710 and 6,670 plants 10a-1. These results indicated that the optimum plant density for those sweet corn hybrids planted in July would be between 5,700 and 6,700 plants 10a-1 in terms of marketable ear yield and quality of marketable ears.

Managing phosphorus for yield and quality of sweet corn grown on high phosphorus soils of Maryland's eastern shore

Reducing P fertilization to address water quality problems has raised concerns among producers regarding crop yield and quality. A 3 yr study was conducted at three sites to examine whether reduction in P fertilization rate and/or use of a preceding rye cover crop affect the yield and quality (sugar concentration and ear weight) of sweet corn (Zea mays L.) grown on soils with “excessive” plant-available P. The experimental design was a split plot with four replications conducted on Norfolk soils. The main plots were no cover crop and a rye cover crop. The subplots were five P fertilizer treatments ranging from 0 to 60 kg P ha-1 at 15 kg P increments. With or without a preceding rye cover crop or P fertilization, postharvest soil test P (Mehlich-1) levels remained “excessive” to a depth of 40 cm. Also, yield of sweet corn was not affected by P fertilization and/or use of a preceding rye cover crop. Without cover cropping, sugar content and ear weight response to P fertilization was positive on site 2 for sugar, and on sites 2 and 3 for ear weight. Utilization of cover cropping positively influenced sweet corn sugar and ear weight sampled at early milk stage without affecting the final yield. In processing sweet corn production, profitability is determined mainly by the yield of marketable ears. Therefore, the small, inconsistent increases in sugar content and ear weight in response to P fertilization, without an increase in yield is not of a major significance to the farmer. On high P soils, P fertilization is unnecessary for the production of quality, high-yield processing corn. The use of a rye cover crop is suggested as a method of reducing the risk of P loss into the surrounding watershed. Key words: Sweet corn yield, sweet corn quality, P fertilization, rye cover crop, phosphorus management, high P soils

Optimum Plant Population for Fresh-market Sweet Corn in the Northeastern United States

There is little published data to support current recommended plant populations of 11,500 to 17,500 plants/acre (28,600 to 34,600 plants/ha) for fresh market sweet corn (Zea mays L.) in the northeastern United States. The plant population likely affects marketable yield and recovery of nitrate. Residual soil nitrate is of concern because of the potential for nitrate contamination of water supplies. Our objectives were to determine the effect of plant population on the yield of sweet corn grown for fresh market without irrigation and on the amount of nitrate in the surface 1 ft (30 cm) of soil at harvest. Seven main-season sweet corn varieties were planted in a total of eight experiments in 1995, 1996, and 1997. Seven experiments were in Connecticut and one was in New Hampshire. All but one of the varieties were standard (su) or sugary enhanced (se) varieties. The experimental design was a randomized complete block with four replications, and the treatments consisted of 12,000, 16,000, 20,000, 24,000, and 28,000 plants/acre (29,600, 39,500, 49,400, 59,300, and 69,200 plants/ha). The yield of marketable ears was classified based on the length of the ears. The results suggest that the current recommendations for plant population in the Northeast US may be too low. Populations of 20,000 and 24,000 plants/acre produced consistently greater yields of ears greater than 7.0 inches (178 mm) long. Soil nitrate-N concentrations at harvest were about 8 mg·kg-1 lower with 16,000 plants/acre or greater, compared with 12,000 plants/acre, which suggests that populations of 16,000/acre or greater should decrease the potential for nitrate contamination of water supplies in the fall, winter, and early spring.

Título en español.

Doce siembras mensuales de maíz dulce se establecieron en la Subestación Experimental Agrícola de Isabela con el propósito de determinar el efecto de la época de siembra en los rendimientos comerciales. En el estudio se incluyeron las variedades 118 Gold Cup, PR 50, Stowell Evergreen, Iobelle, Illinichief Super Sweet, Victory Golden, USDA 34 , AA8 y los hibridos Hawaiian Hybrid y Hawaii 68. El híbrido Hawaii 68 fue el de mejor rendimiento comercial por acre, con un promedio de 15,928 mazorcas. Le siguieron el híbrido Hawaiian Hybrid y las variedades PR 50 y USDA 34, con 11,976, 11,873 y 11,694 mazorcas comerciales por acre, respectivamente. Hawaii 68 y Iobelle produjeron las mazorcas más largas, seguidas por PR 50 y Stowell Evergreen; pero las mazorcas de mayor peso correspondieron a Hawaii 68, Iobelle, Stowell Evergreen, PR 50 y USDA 34, en ese mismo orden. Los datos indican que en siembras de invierno (diciembre, enero y febrero) pueden obtenerse los rendimientos más altos.

Effects of Weed Control Methods on Sweet Corn

Three tractor cultivations that severely pruned the root systems of hand-weeded plots of sweet corn [Zea mays L. var. rugosa Bonaf., Iochief] grown on a Codorus-Elkton silt loam under extreme drought conditions did not reduce the yield of marketable ears when irrigation totalling 2 acre-inches was applied during pollination and ear-filling. Pre-emergence application of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine [atrazine] to the soil surface without cultivation reduced brace root growth and yields significantly in the year of most severe drought. These effects of atrazine were avoided when the herbicide treatments were supplemented with tractor cultivations that covered the brace root zone of the corn plants with soil.