The season is shaping up as another early one. Early varieties are already well into flowering and due to the sustained warm to hot weather we have experienced, flowering will not be far away for the later varieties. As we know, flowering is one of the most critical times of the season in determining the ultimate crop level. A good fruit-set will result in well filled bunches. Successful flowering depends on vines being healthy, having sufficient water and nutrients, balanced rather than excessive growth and good weather. It is still vital that a rigid protective spray program be maintained through flowering and after fruit set. Once the caps fall, the newly-set berries represent a large amount of unprotected tissue, susceptible in particular to Powdery Mildew. Thorough coverage is critical in preventing disease outbreaks later.
Flowering is also a time to consider protection against Botrytis. Many botryticides become unavailable for use due to withholding period restrictions after full bloom (EL25) or when berries are peppercorn size (EL29). While conditions have not yet favoured Botrytis, the application of protection should be considered for susceptible varieties, if you had Botrytis last vintage or if it is likely that your fruit will be held out for high Baumes for concentrate. There have been reports of flights of Light Brown Apple Moth (LBAM) and LBAM larvae have been observed in leaves. Over the flowering period, look for the webbing in bunches that may indicate LBAM is present. If enough of the pest is detected, it may warrant control.
Water management must also be a focus, with growth stages approaching fruit set. While vines should be adequately provided with water, a mild level of stress post fruit-set can help the vines switch their growth cycle from vegetative into fruit development and ripening.