Control of flowering in two commercial sugar-cane varieties

1984 ◽  
Vol 103 (2) ◽  
pp. 333-338 ◽  
Author(s):  
M. A. El Manhaly ◽  
O. Fadayomi ◽  
Y. A. Abayomi ◽  
M. O. Olofinboba

SUMMARYExperiments were conducted over two cropping seasons at the Sugar Cane Estate of the Nigerian Sugar Company, Bacita, Nigeria to determine the effectiveness of additional nitrogen fertilizer, chemical sprays and delayed planting in controlling flowering in two commercial sugar-cane varieties (Co. 1001 andCp. 29/116). Application of 150 and 250 kg N/ha, 8 weeks before initiation, reduced flowering in Co. 1001 by up to 13·5 and 11 % respectively. Flowering was as low as 2% in some of the above treatments while the average flowering in plots with no additional nitrogen application was more than 80%. imilarly, application of diuron (4·0 kg/ha) and paraquat (0'5 kg/ha) to the top leaves (3 weeks before initiation) of Co. 1001 reduced flowering in this variety up to 45 and 35% respectively. Neither the application of diuron and paraquat nor additional nitrogen fertilizer sufficiently reduced flowering in Cp. 29/116. The time of planting affected flowering. Over 85% flowering was observed in November 1982 from Co. 1001 fields planted in January 1982 (10 months before initiation time). However, fields of the same variety planted in June 1982 (4 months before initiation time) did not show any initiation until harvest in May 1983. The implications of the above results are discussed.

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1605
Author(s):  
Yean-Uk Kim ◽  
Byun-Woo Lee ◽  
Sunggi Heu ◽  
Kang-Bo Shim ◽  
Do-Soon Kim

Potato has become one of the staple crops to improve food security in North Korea since the late 1990s. However, the potato yield has been stagnated around 11–12 t ha−1 for several decades, and a food shortage is still a primary issue in North Korea. Yield gap analyses were carried out using the SUBSTOR-potato model to quantify the potato yield gaps and explore the potential ways to close the yield gaps in two different cropping seasons in North Korea (early- and main-season potatoes). Yield gaps were estimated to be around 80% for both early- and main-season potatoes. Early-season potato yield was substantially determined by water or nitrogen supplies, depending on the year’s weather condition (i.e., with or without spring drought). Irrigation during the vegetative stage could effectively reduce the year-to-year variation in yield as well as the yield gap (+7.0 t ha−1, +66.1%). Meanwhile, additional nitrogen fertilizer in the early-season potatoes was less effective compared to that in the main-season potatoes. For the main-season potatoes, where precipitation was sufficient, the primary limiting factor of yield was nitrogen supply. Since heavy rainfall aggravated nitrogen leaching, additional nitrogen fertilizer is recommended as a top dressing rather than a basal dressing. Additional top dressing at 50 days after planting with the current amount of nitrogen fertilizer was expected to increase the main-season potato yield by 42.0 t ha−1 (+191.4%). This study highlights that the primary limiting factor of potato yield may differ between the cropping seasons. Therefore, our findings suggest that different agronomic strategies should be applied for different cropping seasons to improve potato production in North Korea, where agronomic resources are limited.


1981 ◽  
Vol 17 (3) ◽  
pp. 281-289
Author(s):  
P. W. Bartholomew ◽  
R. J. Williams

SUMMARYNitrogen fertilizer requirements and potential forage yield of maize and two millet types grown under irrigation in Saudi Arabia were assessed. Nitrogen application at 50 kg/ha produced mean yields of up to 15.7 t/ha in maize variety Pioneer H.3147. Splitting the nitrogen application did not significantly affect yield. Nitrogen above 100 kg/ha did not significantly increase DM yield of Proso millet (Panicum miliaceum). Mean total DM yields of 17.6 t/ha of Setaria italica were produced, after 111 days, with 150–200 kg/ha of nitrogen; 150 kg/ha of P2O5 produced a mean DM yield 7.9% higher than 75 kg P2O5/ha.


2017 ◽  
Vol 9 (4) ◽  
pp. 236
Author(s):  
Abdulla A. Mohamed Muflahi ◽  
Ahmed Saleh Basuaid

A field experiment was carried out at El-Kod Agricultural Research Station, Abyan Delta, Abyan Governorate during the seasons 2014 and 2015 in soil sandy silt to assess four levels of nitrogen fertilizers (0, 55, 110 and 165 kg N/ha) utilizing urea fertilizer (46% N) on some crop characteristics and efficiency of nitrogen application on two local cultivars of sorghum (Sorghum bicolor L. Moench). Split plot design was applied in four replicates. Fertilizer levels were distributed in main plots whereas, the cultivars in subplots. The results revealed significant differences between cultivars Benny and Saif in all characteristics during the two seasons. Cultivar Benny was significantly superior to cultivar Saif in all crop characteristics, except the length of spike which was significantly superior in Saif cultivar compared to cultivar Benny in both seasons. The increase in nitrogen level led to significant increase in all parameters of crop growth under study in both seasons, where the highest dose of nitrogen (165 kg N/ha) gave highest grain yield (3013 and 3201 kg/ha) in both seasons respectively, while the efficiency of nitrogen utilization declined with increased level of nitrogen application and highest value in nitrogen efficiency (12.78 kg grain/kg N). The interaction between cultivars and nitrogen fertilizer showed significant differences in terms of all studied parameters during both seasons. The cultivar Benny responded to high level of nitrogen (165 kg N/ha) and gave high grain yield (3640 and 3305 kg/ha) in both seasons respectively. The results yielded significant effect for efficiency of nitrogen application on grain yield between the cultivars, the levels of fertilizers and their interaction in the first season whereas, no significant differences were detected in the second season.


1966 ◽  
Vol 2 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Adeboyejo A. Fayemi

SummaryA four-year study from 1958 to 1962 showed that time of application of fertilizer nitrogen greatly influenced the yield of grain, the percentage of nitrogen and the crude protein of the grain under Nigerian conditions characteristic of the early maize cropping season from March to July. Split applications of nitrogen fertilizer significantly increased maize grain yield by 35 per cent when two equal doses were given one month and two months after planting; and by 31 per cent when four equal doses were supplied at planting and one month, two months and three months after seeding. Yield was significantly reduced when application was delayed two months after planting. High yields of maize were not obtained by supplying the whole of nitrogen fertilizer at one time, eidier at sowing or any time later during the growing season. However, applying all of the nitrogen fertilizer one month after planting significantly increased the percentage of nitrogen and of the crude protein content of the grain. The maize ear weight was favourably influenced by spreading the nitrogen application over the three-month period of the maize growth.


1984 ◽  
Vol 24 (125) ◽  
pp. 250 ◽  
Author(s):  
PE Bacon ◽  
DP Heenan

The growth, nitrogen use and yield of rice cv. lnga were examined in three experiments in 1978, 1979 and 1980. In each experiment, one rate of nitrogen was applied at six different times between permanent flood and three weeks after panicle initiation. Application of 50 kg N/ha in 1978 and 70 kg N/ha in 1980 at permanent flood increased yield. A higher rate (100 kg N/ha) at permanent flood in 1979 greatly increased vegetative growth but had little effect on grain yield. The grain yield response to 100 kg N/ha in 1979 significantly increased when application was delayed until panicle initiation. Nitrogen topdressing up to 14 d after panicle initiation resulted in an increased percentage of filled florets per panicle and heavier grains compared with application 14-21 d before panicle initiation. Delaying nitrogen application till 2 1 d after panicle initiation resulted in lower numbers of florets per panicle and consequently reduced yield.


1996 ◽  
Vol 32 (1) ◽  
pp. 63-66
Author(s):  
N. E. A. Malenga

SUMMARYThe response to nitrogen of four high yielding good quality clones of tea was investigated on fertile virgin soil. The yields of all the clones examined were maintained without additional nitrogen during the first two years after planting but Clone PC 81 responded to nitrogen in the second year after planting. This was the earliest recorded stage at which seedling or clonal tea had responded to nitrogen in Malawi. The other clones examined all responded to nitrogen in the third year after planting, and the yields of all the clones were substantially increased by the higher rates of nitrogen applied in the early years after planting, though the responses to nitrogen differed between seasons.


1984 ◽  
Vol 103 (3) ◽  
pp. 659-669 ◽  
Author(s):  
D. Reid

SummaryIn studies of the seasonal distribution of nitrogen fertilizer dressings on grassland using conventional experimental designs it is usually not possible to separate the true effects of an individual fertilizer dressing on the yield at a particular cut from the residual effects of previous dressings. An experiment is described which was designed to allow separation of the direct and residual effects, with certain restrictions, for a system involving five cuts and five possible fertilizer dressings per season on perennial ryegrass swards. From the results obtained over two harvest years on swards on two adjacent sites equations were derived relating the dry-matter and crude-protein yields of herbage to the rate of nitrogen application at five dressings in the season. Predictions of yield distribution patterns from the equations are compared with observed yields from various sequences of nitrogen dressings included in previous experiments at this Institute. Examples are also given of the prediction of sequences of nitrogen dressings required to obtain certain patterns of yield distribution.


2013 ◽  
Vol 316-317 ◽  
pp. 250-253
Author(s):  
Hong Chang ◽  
Xin Bin Zhou ◽  
Shu Hui Yu ◽  
Yong Xiang Zhou

Effects of nitrogen on uptake, accumulation and partitioning of zinc throughout the development of wheat were studied under pot-culture conditions. The results showed that under low zinc application (0.2 mg kg-1) the grain zinc content increased by 140% when nitrogen fertilizer increased from 50 mg kg-1 to 150 mg kg-1. Under high zinc application (5 mg kg-1) the grain zinc content increased by 61%. Increasing nitrogen application under low zinc fertilizer, the grain zinc mainly comes from the root zinc uptake. While increasing nitrogen application under high zinc fertilizer, the grain zinc mainly comes from the straw zinc remobilization.


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