Interactive effects of leaf pulling and non-toxic chemical interventions on rot management in north central region vineyards

Commodities

Practices

Grape production is a growing industry in the North Central
region, which includes juice, wine, and table grape production.
Successful grape production relies on high quality fruit to make
excellent juice and wine, but growers in this region face high
risk of cluster rots in vineyards, mainly caused by fungal and
bacterial infections such as botrytis bunch rot and sour rot. The
vinegar fly Drosophila melanogaster is often associated
with sour rot. These rots are favored by the humid
microenvironment around the cluster. The cultural practice of
leaf pulling to reduce humidity is effective against cluster
rots, but that must be done early in the season, and it reduces
yield. Another approach is to use antimicrobials and insecticides
near harvest to manage sour rots, but resistance developing in
D. melanogaster necessitates exploring non-toxic
alternatives. Here, I aim to investigate the effect of non-toxic
chemical alternatives on Drosophila species, by
assessing attraction, fecundity, survival, and larval
development. The most effective treatments will be tested in two
commercial vineyards in a factorial experiment in combination
with leaf pulling for 2 seasons. The objectives are to:

1. Determine the effects of non-toxic chemical alternatives on
   the behavior and life-table components of Drosophila
   melanogaster in the laboratory
2. Determine sour rot control and economics from combining
   effective cultural and chemical treatments

I hypothesize that Drosophila melanogaster will be less
successful on grapes in response to the non-toxic chemical
alternatives compared to control. I also expect these effects
will vary among the different treatments. I also hypothesize that
sour rot infestation will be lower when effective non-pesticide
treatments are combined with leaf pulling treatment.

My project will include an educational component, introducing
farmers to the insect’s role in cluster rot and the available
non-toxic chemical interventions. I will share my results through
farmer field days, a grower-oriented newsletter article and a
scientific publication. The impact of my study will be determined
by farmer responses to pre-and post-study evaluations of their
approaches to cluster rots, the role of insects and their
management, and from metrics such as visits to the online
extension article and farmer adoption after project completion.

As a learning outcome, growers will learn about the insect and
pathogen causal agents of cluster rots and the importance of
insects. They will also acquire knowledge on non-toxic chemical
alternatives to address resistance issues in vineyards. Growers
will gain practical knowledge and skills of integrating leaf
pulling with chemical interventions through a grower-oriented
article and field days. My research will offer an alternative,
eco-friendly option for cluster rot management, improving the end
product quality in commercial and organic vineyards. Growers will
advance their knowledge on alternative options to toxic chemical
interventions for cluster rot management, leading to
better-quality end products. Researchers and educators will
identify new non-toxic interventions and can extend
recommendation options to growers. As an action outcome, growers
can substitute or integrate these products and practices into
their rot management strategies, allowing expansion of
sustainable practices. Researchers will leverage new studies
based on our findings from this project.