Mr Atherton tried to contact Mr Waho at 11.21am to make sure he was not spraying as it had become too windy. He left a message then, and a further message at 3.43pm.
Mr Atherton also looked for Mr Waho but could not find him.
At the morning meeting the next day, Mr Atherton asked Mr Waho if he had received his message, to which he responded he did not but he "only did one knapsack [of spray] anyway".
Mr Waho left work about 11am that day due to heatstroke and was away for the next two days.
Mr Waho had also been absent during winter "due to the cold and the wet", so an employment relations meeting was called to discuss those issues, the spray issue and to consider whether Mr Waho's position was redundant given other staff had had to cover for him so much.
Mr Waho was told on December 21 that his position was terminated, with two weeks' notice, for failing to comply with an instruction.
The authority said it was obvious Mr Waho had a "chequered" employment history, evidenced by previous warnings. He was on a final warning when the spraying incident occurred.
Pencarrow Stud's actions were that of a "fair and reasonable employer" and Mr Waho's dismissal therefore justified. APNZ