Effects of potassium management on enzyme activity and cotton fiber cellulose content

Abstract

Background Potassium (K) is prone to be washed out of plant tissues independent of mineralization since it is not strongly bound to organic structures in the plant. Therefore, cover crops can enhance K cycling in cropping systems increasing the nutrient use efficiency by taking it up deep in the soil profile and releasing it on the soil surface. However, it is not clear if this cycling would have an effect on cotton morphophysiology, enzyme activity, and eventually on fiber quality. Results Cotton leaf area index was increased late in the season by K, with small differences between fertilized treatments, but was highest at full bloom when at least part of the K was applied to cotton Consequently, the enzymatic activity and accumulation of cellulose in the cotton fiber were also increased. Conclusions Potassium fertilization improves cotton physiological parameters such as leaf area index, but the effect on enzyme activity depends on the enzyme and on the cotton cultivar. Early cellulose accumulation in the fiber is favored by potassium fertilization and cotton rotation with ruzigrass.

Zonal Application of Plant Growth Regulator in Cotton to Reduce Variability and Increase Yield in a Highly Variable Field

“…Different doses for each zone in 2020 (Table 2) were defined based on plant height measurements in the three zones taken between 35 and 60 DAS (Fig. 6) and on previous experiences in that area regarding plant growth due to in-season climate variation, application of fertilizers, and cultivar following the State of Mato Grosso Best Management Practices Manual (Echer et al, 2020), resulting in 32.5 g ai ha -1 for Z3 (lowest dose applied), 55 g ai ha -1 for Z2 (highest dose applied), and 40 g ai ha -1 for Z1.…”