Black Nightshade

Key Points

Black Nightshade is very competitive with crops of forage maize
Livestock can be poisoned if they consume ripe berries
Starane 2 controls Black Nightshade and many other broad-leaved weeds
Do not apply in tank mix or if buttress roots have started to develop

Introduction

Black Nightshade — Solanum nigrum — is a common weed of wasteland and, more importantly, frequently thrives in crops of forage maize. Poor crop competition early in the season allows Black Nightshade to establish and flourish before the crop canopy closes. An additional and very significant problem associated with the presence of Black Nightshade in crops of forage maize is the potential for livestock to be poisoned by consuming the berries. Signs of poisoning include difficulty in breathing, digestive system disturbances, dilated pupils and loss of coordination. Professional treatment is required as severely affected animals can die.

Biology

Fluctuating spring temperatures are required to promote germination of Black Nightshade seeds. The first seedlings are normally observed in late April or early May, coinciding with the time forage maize crops are drilled. The plant varies in size from 15cm, lying close to the ground, up to bushy plants of 60cm. Branching stems carry oval or diamond-shaped leaves, sometimes with wavy edges, and clusters of small white flowers with pointed petals appear in summer. Ripe fruits are shiny, black, spherical berries containing numerous seeds.

Product Choice

Starane* 2 (active ingredient fluroxypyr) is recommended for the control of Black Nightshade in forage maize crops. Starane 2 will control plants from cotyledon size up to 6 true leaves. It will not control Black Nightshade that has not emerged at the time of application.

Treatments should be made when forage maize is between the 3 – 6 leaf stage and before the crop is over 20cm tall. Do not make applications once the buttress roots have started to develop at the first node. Do not apply Starane 2 to forage maize in tank mix with any other product.