(S (S (PP (VBG According) (PP (TO to) (BASENP (NNP Whitley)))) (COMMA ,) (S (S (NP (BASENP (JJ certain) (JJ atmospheric) (NNS conditions)) (PRN (COMMA ,) (PP (IN such) (PP (IN as) (NP (BASENP (NN wind) (NN speed)) (CC and) (BASENP (NN humidity))))) (COMMA ,))) (VP (MD must) (VP (VB be) (ADJP (JJ right))))) (SBAR (IN before) (S (BASENP (DT the) (JJ large) (NN scale) (NNS treatments)) (VP (MD can) (VP (VB occur))))))) (PERIOD .))