Effect of NPK Rates and Humic Acid Applications on Growth of Egyptian Cotton

Abstract

Two field experiments were carried out at Gemmeiza Agric. Res. Station, El-Gharbia Governorate during 2010 and 2011 seasons, to study the effect of four NPK fertilizers rates (100 %, 75 %, 50 % and 25 % of recommended rate) and application methods of humic acid on growth of the Egyptian cotton cultivar "Giza 86". The recommended rate of NPK was 45 kg N +22.50 kg P2O5 + 24.0 kg K2O/ fed.. The solutions of humic acid were applied with the concentration of 5 cm 3 /litre as a soaking seed for 18 h, 50 cm 3 /litre as soil application twice , 5 cm 3 /L as a foliar application at 40, 55 and 70 days from sowing and without humic acid as a control treatment. Leaf area index (LAI), total dry weight/plant, crop growth rate (CGR), plant height and number of fruiting branches/plant were significantly increased by increasing NPK rate from 25 up to 100% of the recommended rate at all sampling dates in both seasons. Also, application of 100% NPK recorded the highest net assimilation rate (NAR) at the first period (79-100 days) in the two seasons. Application of humic acid solution resulted in a significant increase in all mention growth measurements (except NAR) compared with control treatment in both seasons. Foliar application of humic acid resulted in a significant increase in leaf area index, total dry weight/plant, crop growth rate, plant height and number of fruiting branches/plant compared with other application methods in both seasons. The interaction between NPK rate and humic acid application had a significant effect on LAI, total dry weight/plant, CGR and NAR at the most sampling dates in the two seasons. Plants received 100 or 75% NPK along with foliar application of humic acid produced higher LAI, total dry weight/plant and CGR than those received 25 % NPK and without humic acid at the most sampling dates in both seasons. The relative ranking of the interaction between NPK rate and humic acid application for NAR was inconsistent at the two period in both seasons. None of the interaction had a significant effect on plant height and number of fruiting branches / plant in the two seasons. It can be concluded that 75% NPK and foliar application with humic acid could be recommended for optimum dry matter production of the Egyptian cotton cultivar "Giza 86". This result indicated that foliar application of humic acid can be saved 25% NPK fertilizer without reduce growth of cotton plant.

Effect of Foliar Application with Micronutrients under Different Fertilizer Levels on Cotton Cultivar Giza 94

“…The boll weight and seed index increases due to the high NPK level was mainly attributed to increase photosynthetic activity of cotton plants and consequently increase accumulation of metabolites with direct impact on boll weight and seed index. These results are in accordance with those outlined by overall plant growth, fruit retention, seed cotton yield and its components, Seadh et al, (2012), Emara et al, (2015 and2016), Elhamamsey et al, (2016) and Emara and Abdel-Aal (2017c). The micronutrients treatments had a significant effect on number of open bolls/plant and boll weight in 2016 and 2017 seasons and seed cotton yield/feddan in 2017 season only, but the insignificant effect on, seed index and lint percentage in both seasons.…”

“…In this respect Seadh et al, (2012) and Hamoda et al, (2014) found that the final plant height, no. of fruiting branches/plant, number of bolls/plant, boll weight, seed index, lint percentage and seed cotton yield/plant and /fad.…”

Studies on Response of African Marigold (Tagetes erecta) to NPK, Humic Acid and Zinc Sulphate in Red and Lateritic Soils of Jhargarm District of West Bengal

“…Table 1. Maximum plant height (67.6 cm) was observed applying T3 [7], the performance of plant growth parameters changed with humic acid and the NPK application rate and the plants had better growth under maximum concentration. Nutrient uptake, especially of nitrogen, phosphorous and sulfur is improved by the activity of humic acid [8].…”

The role of a novel fungal strainTrichoderma atrovirideRVF3 in improving humic acid content in mature compost and vermicompost via ligninolytic and celluloxylanolytic activities

“…Foliar spray of humic acid at the rate of 0Á1% showed a significant increase in uptake of nutrients than the control (Tenshia and Singaram 1992). Increased plant growth by application of humic acid was observed in Gerbera jamesonii L. (Nikbakht et al 2008), cotton (Seadh et al 2012), wheat (Mackowiak et al 2001), cucumber (Rau- than and Schnitzer 1981) and marigold, pepper and strawberry plants (Arancon et al 2006).…”

“…), cotton (Seadh et al . ), wheat (Mackowiak et al . ), cucumber (Rauthan and Schnitzer ) and marigold, pepper and strawberry plants (Arancon et al .…”