Potassium Management for Improving Processing Tomato Yield and Quality in Xinjiang

IPNI-2012-CHN-XJ4

29 Apr 2016

2015 Annual Interpretive Summary


The objectives of this study are to determine the appropriate ratio of KCl application for processing tomato through the evaluation of fruit yield/quality, economic benefit, and Cl- accumulation in the soil profile.

Equally splitting the total K application (as KCl), between flowering and fruiting stages produced more total aboveground dry matter, single fruit weight, and fruit yield as well as less total acid content than either KCl+K2SO4 or K2SO4 alone. Basal application of 50% or 70% of the K recommendation as KCl in the fall, along with adding the the remainder as K2SO4 at fruiting produced similar yield to farmer practice (FP) of split applying K2SO4. Applying 30% or 50% of the K as K2SO4 at fruiting increased fruit yield and fruit solid content by 30% to 50% versus application at flowering. The combination of KCl+K2SO4 generated similar income to FP. Equally split applications of KCl between flowering and fruiting stages produced more income over KCl+K2SO4 or FP. Higher KCl application created higher Cl- contents in the 0 to 60 soil layer and the Cl- concentration in soil profile increased with soil depth.

Further field demonstrations showed that 70% of the recommended K applied basal as KCl, together with 30% topdressed as K2SO4 at fruiting stage produced more dry matter, fruit yield, and economic income than with the 30% provided as K2SO4 applied at flowering, or FP. Application of KCl did not negatively affect tomato fruit quality. Combined application of KCl and K2SO4 did not affect fruit K and Cl- content and did not cause Cl- accumulation in soil.

In summary, basal application of 70% of the K recommendation as KCl during the fall combined with the adding the remaining K as topdressed K2SO4 at fruiting can result in better tomato fruit yield/quality, more economic benefit, and little Cl- accumulation in soil. This practice can be a recommended K management practice for drip-irrigated processing tomato production in Xinjiang.