R. L. Yadav

Low temperature stress-induced biochemical changes affect stubble bud sprouting in sugarcane (Saccharum spp. hybrid)

A laboratory experiment was conducted to study the effect of low temperature stress on stubble bud sprouting and associated biochemical changes in sugarcane (Saccharum spp. hybrid). At 25°C, stubble bud sprouting was about 80%, whereas at 15 and 6°C, it was 56% and 23%, respectively. In stubble buds, the levels of reducing sugars and acid invertase were low, while IAA, total phenols and proline contents were high at low temperatures, as compared to normal temperature (25°C). Similarly, the specific activities of antioxidant enzymes, viz., catalase and peroxidase in stubble buds were higher at low temperatures than at normal temperature. The results indicate that poor sprouting of stubble buds at low temperatures appears to be due to a reduced availability of reducing sugars concomitant with a lower activity of acid invertase. An increased level of IAA together with toxicity build-up in situ due to an accumulation of total phenols may be responsible for the maintenance of dormancy in stubble buds at low temperatures. On the other hand, higher activities of catalase and peroxidase enzymes may protect stubble buds from an oxidative damage, while proline accumulates to act as an osmoprotectant under low temperature stress.

Recycling of Organic Wastes Amended with Trichoderma and Gluconacetobacter for Sustenance in Soil Health and Sugarcane Ratoon Yield in Udic Ustochrept

A field experiment was conducted with the objectives to relate the changes in the physical properties, soil organic carbon (SOC), nutrient availability, and uptake and output input ratios for sustaining sugarcane ratoon growth and yield in an Udic ustochrept. Eight combinations of trash and farmyard manure (FYM) with and without Trichoderma viride and Gluconacetobacter diazotrophicus were applied in two sugarcane ratoon (first and second ratoon in succession) crops. Application of Trichoderma-enriched trash showed the lowest bulk density (1.36 Mg m−3) and the greatest infiltration rate (4.5 mm h−1). Greater rate of increase in SOC was observed under inoculation of Trichoderma with FYM compared to trash mulch. The output/input ratios were greater in plots having trash-based treatments compared to FYM and inorganic fertilizers. Bioagent-inoculated FYM produced greater mean sugar yield (8.89 t ha−1) compared to bioagent-inoculated trash (7.97 t ha−1).

Bio-organic Amendment of Udic Ustochrept Soil for Minimizing Yield Decline in Sugarcane Ratoon Crops under Subtropical Conditions

The effects of subsequent sugarcane ratooning on soil quality and the crop yields under four treatments [an absolute control (T0), application of recommended dose of nitrogen (N)–phosphorus (P)–potassium (K) (T1), application of sulfitation press mud (SPM), a sugar factory by-product (T2), and SPM along with Gluconacetobacter diazotrophicus (Gd, T3)] were evaluated for 7 years. In the control (T0) and NPK-fertilized (T1) plots, an increase in soil compaction (5.4%), decrease in infiltration rate (6.04%), lower microbial activities, and increased soil phenolic contents (72.4%) rendered the nutrients unavailable, leading to significant declines in the crop yields at the rate of 5.47 Mg ha−1 y−1 and 4.67 Mg ha−1 y−1, respectively. The crop yield declined from 53 kg ha−1 in plant crop to 18 kg ha−1 in the sixth ratoon crop under the absolute control. The rates of yield decline, however, were minimized in SPM (T2) and SPM + Gd (T3) plots to 3.54 and 3.51 Mg ha−1 y−1.

Soil-Root Interface Changes in Sugarcane Plant and Ratoon Crops under Subtropical Conditions: Implications for Dry-Matter Accumulation

Poor sugarcane ratoon yields in the subtropics are responsible for decrease in overall productivity and poor sugar recovery. The present work is an attempt to assess reasons for decline in crop productivity despite providing adequate inputs. The simultaneously initiated plant and ratoon crops were compared for dry-matter accumulation and its distribution pattern in relation to changes in soil-root interface environment. In spite of well-established root system and advanced sprouting and tillering during the formative phase, dry-matter accumulation and nutrient uptake were low in a ratoon crop and were more apparent 120–210 days after planting. This decrease in nutrient uptake was due to declines in soil cation-exchange capacity, nitrate reductase (NR) activity in vivo by 19.4 and 25.9 percent, and increase in percentage leakage by 11.26 percent. These alterations at the soil-root interface in ratoons functioned as barriers for nutrient uptake and affected overall physiological growth and dry-matter accumulation adversely.