Integrated Management of Sclerotinia Blight in Peanut: Utilizing Canopy Morphology, Mechanical Pruning, and Fungicide Timing

Abstract

Sclerotinia blight of peanut, caused by Sclerotinia minor, generally becomes severe only after vines meet in the row middles and a dense canopy develops. Dense foliage appears to support a microclimate conducive to the colonization of peanut limbs by S. minor. Removal of excess foliage before and during a Sclerotinia blight epidemic on the susceptible genotype NC 7 has been shown to reduce the rate of disease progress. Field tests in 1993 and 1994 examined control of Sclerotinia blight among four peanut genotypes (NC 7, VA 93B, NC Ac 18016, and Tam-span 90) with diverse canopy morphologies. Each cultivar had foliage pruned with a rotary mower once (1993 and 1994) or twice (1994) during the season. Applications of fluazinam (9.2 kg a.i./ha) were imposed on the genotype × pruning treatments. Soil temperatures under the canopy of each genotype and pruning treatment were measured and compared. Disease data were collected weekly by counting the number of feet of plants exhibiting lesions with visible fungus growth. Tamspan 90, a resistant Spanish peanut, had the least Sclerotinia blight incidence. Pruning measurably affected soil temperature for approximately 2 weeks following pruning. Removal of foliage reduced disease and increased disease control affected by fluazi-nam in fields with high disease pressure. In some tests, yields were increased by pruning through a reduction in disease pressure. Yields were lower when peanuts were pruned excessively, especially late in the season. Pruning of excessive vine growth can be an alternative, or complement, to fungicide treatments when done in midseason during favorable weather when moderate to high disease pressure occurs.

Fine-Mapping the Branching Habit Trait in Cultivated Peanut by Combining Bulked Segregant Analysis and High-Throughput Sequencing

“…However, the pods of bunch/erect plants develop at the same time, promoting early maturation. The growth habit of peanut affects the implementation of agrotechnology such as mechanical cultivation and disease management (Butzler et al, 1998). …”

Management of Stem-rot of Groundnut (Arachis hypogaea L.) Cultivar in Field

“…Butzler et al (1998) stated that plant-toplant infection of Sclerotinia blight of peanut (Sclerotinia minor Jagger) occurs after canopy closure and concluded that further spread of the disease could successfully be reduced by mowing excess foliage after disease pressure was evident. By the introduction of mycorrhizal fungi the incidences of disease was also lower in mycorrhizal treated groundnut plant than there non-mycorrhizal pathogenic plants.…”

Chemical Control of Peanut Diseases: Targeting Leaves, Stems, Roots, and Pods with Foliar-Applied Fungicides

“…The application of benomyl in conjuntion with the pruning of peanut vines increased stem rot control (Backman et al, 1975). Likewise, the application of iprodione following pruning has improved control of Sclerotinia blight (Bailey and Brune, 1997;Butzler et al, 1998). Implements designed to open the canopy have been used to concentrate fungicides near the crown area.…”